Conventionally, a polymer of a compound having a phosphorylcholine group has been known as a biocompatible polymer and biocompatible materials in which various substrates are coated with this polymer have been developed.
Therefore, a method of utilizing a powder coated with a homopolymer and copolymer of 2-methcryloyloxyethylphosphorylcholine as a powder for cosmetic material to provide a cosmetic material with improved moisture retention and skin adhesion properties has been proposed (for example, see Japanese Patent Application Publication No. 07-118123). A medical material and separating medium coated with a polymer having a phosphorylicholine group have also been disclosed (for example, see Japanese Patent Application Publication No. 2000-279512 and Japanese Patent Application Publication No. 2002-098676).
Furthermore, the above-mentioned material is a polymer obtained by synthesizing a monomer having a phosphorylcholine structure and polymerizing it, wherein principally an acrylic monomer having a hydroxyl group and 2-chloro-1,3,2-dioxaphosphorane-2-oxide, and further trimethylamine are reacted to provide a quaternary ammonium.
For such a compound, a method for manufacturing a copolymer of 2-methecryloyloxyethylphosphorylcholine and a methacrylate ester is disclosed (for example, see Japanese Patent Application Publication No. 09-003132).
For a similar compound, a method for manufacturing a homopolymer of 2-methacryloyloxyethylphosphorylcholine is disclosed (for example, see Japanese Patent Application Publication No. 10-298240).
However, synthetic conditions are complex and there are problems in safety in regard to the above-mentioned methods for manufacturing a polymer having a phosphorylcholine group as disclosed in Japanese Patent Application Publication No. 07-118123, Japanese Patent Application Publication No. 2000-279512, Japanese Patent Application Publication No. 2002-098676, Japanese Patent Application Publication No. 09-003132, and Japanese Patent Application Publication No. 10-298240.
Furthermore, it is difficult to coat the entire surface of an object effectively, and even if a costing is made, there is a problem of its easy release from the object, in regard to a polymer having a phosphorylcholine group and method for coating and modifying a surface of an object with the polymer as disclosed in Japanese Patent Application Publication No. 07-118123, Japanese Patent Application Publication No. 2000-279512, Japanese Patent Application Publication No. 2002-098676, Japanese Patent Application Publication No. 09-003132, and Japanese Patent Application Publication No. 10-298240.
Moreover, the entire surface of an object is coated with a polymer having a phosphorylcholine group, and therefore, only the phosphorylcholine group is not necessarily exposed on the surface, depending on a steric structure which is allowed to have by the polymer. Therefore, there is a problem that a surface-modifying method having a complete biocompatibility is not necessarily provided.